Children's early numeracy knowledge predicts later academic performance, yet many children do not experience optimal math instruction. This study investigated the impact of academic service-learning (ASL) in an early childhood teacher preparation math course and answered the following research question: Was the ASL experience effective in improving students' dispositions and self-efficacy for teaching early math? Participants included nine undergraduates in an early childhood teacher preparation course and thirteen 2- to 5-year-old children from ten culturally and linguistically diverse families. Results of this mixed-methods study indicated the university students expressed considerable math anxiety near the beginning of the course, yet they believed in the importance of math and aspired to support children's math. Students articulated challenges and assumptions related to supporting early math. A key finding was that, across the ASL experience, students experienced a shift away from anxiety and toward self-efficacy for teaching math and a disposition to advocate for early math. Children's math knowledge was also assessed and was significantly higher post-ASL than pre-ASL. The article concludes with a discussion of the obligation of early childhood teacher preparation programs to address possible math anxiety among preservice teachers and provide experiences that help students build self-efficacy for teaching math.